A cost breakdown structure (CBS) is simply a way of breaking down and organizing costs in a structured fashion. If you have experience with project management, you will probably be familiar with the concept of a work breakdown structure (WBS). The Mandrel CBS is very similar, but since Mandrel can be used for other applications besides project budgets, we use the more generic term cost breakdown structure.

A screenshot of the Mandrel Cost Breakdown Structure formA screenshot of the Mandrel Cost Breakdown Structure form
Mandrel provides extensive facilities to create, edit, modify, and re-use cost breakdown structures.

A CBS consists of a series of linked cost items. Other terms you may be familiar with are tasks or line items. A single Mandrel CBS can contain up to 10,000 cost items.

A CBS is shaped like an inverted tree. At the top is the level zero item, from which the entire structure descends. Mandrel creates the level zero item for you when you open a new project. You then fill in the lower levels (level 1, level 2, and so on). Alternatively, you can take the CBS from an existing Mandrel project and modify it to suit your current project.

Generic cost breakdown structure
Generic cost breakdown structure
Mandrel provides capabilities to add, insert, delete, move and name items in a CBS. Numbering is automatically adjusted whenever a change is made to the structure so as to remove any gaps or duplications caused by the change. This means you don't have to thinks about the mechanics of changes, but only the end result you want to achieve.

You can either use a decimal numbering system (1.2.3. ...) or a fixed-digit numbering system (1230 or 12300, etc.). Fixed-digit systems can use up to 9 digits.